- Skin test positive (skin prick test with a wheal diameter at least 3 mm larger than the diluent control or intradermal testing with the wheal diameter at least 7 mm larger than diluent control) at Screening, or within 12 months prior to the Screening Visit, to an appropriate seasonal allergen, including one or more of the following: Kentucky bluegrass (Poa pratensis)grass: meadow fescue, rye, Bermuda grass trees: oak, maple, birch cat hair or dander (Felis domesticus) ragweed